1. Field of the Invention
The present invention relates to sheet transportation devices, particularly a sheet transportation device including an electromagnetic component.
2. Description of the Related Art
A device configured to transport a sheet (original document, recording paper, and the like) such as an image formation apparatus conventionally employs an electromagnetic component such as a solenoid, motor, and actuator. As used herein, an electromagnetic component refers to a component utilizing electromagnetic force, functioning in the device through electromagnetic force. In such components utilizing electromagnetic force, terminating the application of current for inducing a magnetic field causes counter electromotive force, i.e. electromotive force to cancel change in the magnetic field caused by terminating application of current.
Japanese Laid-Open Patent Publication No. 2008-164999 discloses the approach to absorb counter electromotive force induced in a motor by means of a diode connected parallel to an interlock switch in order to avoid damage at a drive unit caused by a current through counter electromotive force in a printer, a multifunction device, or the like.
In the field of such devices, there is a constant demand for improving the reliability of the device by preventing damage to components, as well as reducing power consumption. Japanese Laid-Open Patent Publication No. 05-193230 discloses a printer device directed to realizing reliability and reduction in power consumption. There is disclosed the approach to control the ON/OFF of a power supply periodically to actuate a sensor, and latch the output signal from the sensor according to a timing signal related to the timing of the ON/OFF control.
The technique disclosed in Japanese Laid-Open Patent Publication No. 05-193230 does not take into account induction of counter electromotive force that is a conventional problem.